Merging upstream version 1.68.2+dfsg1.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 30 insertions, 0 deletions

diff --git a/tests/ui/impl-trait/example-st.rs b/tests/ui/impl-trait/example-st.rs
new file mode 100644
index 000000000..4e1aa3a08
--- /dev/null
+++ b/tests/ui/impl-trait/example-st.rs
@@ -0,0 +1,30 @@
+// run-pass
+
+struct State;
+type Error = ();
+
+trait Bind<F> {
+    type Output;
+    fn bind(self, f: F) -> Self::Output;
+}
+
+fn bind<T, U, A, B, F>(mut a: A, mut f: F)
+                       -> impl FnMut(&mut State) -> Result<U, Error>
+where F: FnMut(T) -> B,
+      A: FnMut(&mut State) -> Result<T, Error>,
+      B: FnMut(&mut State) -> Result<U, Error>
+{
+    move |state | {
+        let r = a(state)?;
+        f(r)(state)
+    }
+}
+
+fn atom<T>(x: T) -> impl FnMut(&mut State) -> Result<T, Error> {
+    let mut x = Some(x);
+    move |_| x.take().map_or(Err(()), Ok)
+}
+
+fn main() {
+    assert_eq!(bind(atom(5), |x| atom(x > 4))(&mut State), Ok(true));
+}